C# Defined Arrays

Can I define 开发者_高级运维an array such that the first element is String, the Second is an int and the third is a textbox?

It's like when we create a List we choose type of element List<string >

Update from Comment:

Sorry I couldnt explain.I need to like this List<string,int,object> Firstly i will set type and when i call the list i will not need to cast

thanks

create list of objects. in C# everything is derived from object

List<object> list = new List<object> {"first", 10, new TextBox()};

EDIT(To comment):

Then you should create seperate class to hold those three items , or use Tuple

List<Tuple<string,int,TextBox>> list;

You can declare an array of object and do that. You're talking about a mixed type array, right?

var arr = new object[] { "Hi", 42, 3.7, 'A' }

If you need an array that has elements without a common base-class other than object, then you're going to need an array of objects!

object[] myArray = new object[] { "Hi", 23, new TextBox() };

Note that this is not really something you should doing. If you need to associate disparate types like this, a class makes much more sense.

You want a Tuple<string,int,TextBox>, not an array.

IMHO the best way to do this is through a List<> of objects:

String  s = "hey!";
int     i = 156;
TextBox t = new TextBox();

List<object> list = new List<object>(3);

list.Add(s);
list.Add(i);
list.Add(t);

The reason this works is because (almost?) everything in C# derives from the base-class object

Arrays are typically homogeneous collections, which means that every object contains in the array is of the same type (or at least shares a common parent type). An array of [string, int, textbox] could be defined as an object[] but that's really misuse of arrays.

Just create a proper class which contains the 3 fields.

class MyType {
    public string myString;
    public int myInt;
    public Listbox myListbox;
}

If you're looking make a list of string, int, textbox, you can either create a class which has those members or look at the Tuple class in .net 4.0

List<Tuple<string,int,TextBox>

Define a class that contains the 3 types then define an array that contains the new type.

Object[] myObjects = new Object(){"myString", 42, textbox1};

System.Collections.Generic.Dictionary<string, object> source = new System.Collections.Generic.Dictionary<string, object>();


source.Add("A", "Hi");

source.Add("B", 10);

source.Add("C", new TextBox());

While accessing

string str = Convert.ToString(source["A"]);

int id = Convert.ToInt16(source["B"]);

TextBox t = (TextBox)source["C"];

I will suggest that you create a Type such as

enum ItemType { Int, String, Textbox }
class MyType {
    public object objValue;
    public ItemType itemType;
}
List<MyType> list = new List<MyType>();
.......

You can iterate through the list or extract the list by type such as below.

var intList = list.Where(e=>e.itemType == ItemType.Int);

Of course you can achieve the above with the enum and using the reflected Type info directly from the object, but I just think it is clearer this way also more explicitly list out the type your list can hold rather than just all type in the CLR